All publications mentioned throughout this application are fully incorporated herein by reference, including all references cited therein.
Zinc-desferrioxamine (Zn-DFO) and gallium-desferrioxamine (Ga-DFO) are metal complexes, previously shown by the inventors to inhibit the catalysis of iron (and copper) in the formation of free radicals. Their protective activity can be visualized through the “pulling” out of available and redox active iron that is responsible for the production of the hydroxyl radicals via chelation by the DFO component. At the same time, the relatively inert zinc (or gallium) ion, that is liberated during the exchange of iron within the complex, further acts as a secondary antioxidant, by “pushing” out an additional iron ion from a binding site [Chevion, M. (1988) Free Radic Biol Med 5, 27-37; Chevion, M. (1991) Free Radic Res Commun 12-13, 691-6]. The spatial structure of these complexes is markedly different from that of DFO alone, allowing for enhanced infiltration into cells and tissues [Chevion et al. (1991), ibid]. There has been a report that high dose DFO can inhibit lymphproliferation, IgE production and IL-4 gene expression in HgCl2-induced autoimmunity in BN rats [Zu et al (2004), Clin. Exp. Immunol 135, 194-199]. In addition, DFO was reported to attenuate minor lung injury following surgical acute liver failure [Kostopanagiotou et al, (2009) Eur. Respir. J. 33:1429-1436]. In previous studies, the inventors have shown that systemic treatment with Zn-DFO and Ga-DFO reduced damage to the retina subjected to ischemia and reperfusion, in accord with their enhanced infiltration through the blood-retinal barrier [Ophir, A. et al. (1994) Invest. Ophthalmol Vis. Sci. 35, 1212-22; Banin, E. et al. (2000) Free Radic Biol. Med. 28, 315-23]. Likewise, topical application of Zn-DFO reduced corneal damage following alkali burn [Siganos, C. et al. (1998) Cornea 17, 191-5]. A previous publication of the inventors, WO 2004/060490, concerns the use of topical application of Zn-DFO and Ga-DFO in reducing ocular damage following exposure to nitrogen and other mustard gases, as well as other warfare agent, e.g. Sarin, which inflict injury through different mechanism. In the present invention, the inventors surprisingly demonstrate the beneficial effects imparted by Zn-DFO and Ga-DFO in the treatment of different immune-related disorders including asthma, diabetes mellitus type II and I, and psoriasis.
Asthma
Asthma is a chronic inflammation of the lungs in which the airways (bronchi) are reversibly narrowed. Asthma affects 7% of the population, and 300 million worldwide. During attacks (exacerbations), the smooth muscle cells in the bronchi constrict, the airways become inflamed and swollen, leading to breathing difficulties. The frequency of acute asthmatic attacks depends on asthma severity. Acute asthma exacerbations cause 4,000 deaths a year in the U.S. Attacks can be prevented by avoiding triggering factors and by drug treatment. Drugs are used for acute attacks, commonly inhaled beta-2 agonists. In more serious cases, drugs are used for long-term prevention, starting with inhaled corticosteroids, and then long-acting β2-agonists if necessary. Leukotriene antagonists are less effective than corticosteroids but have no side effects. Monoclonal antibodies such as mepolizumab and omalizumab are sometimes effective.
According to several reports, asthma attacks are associated with a significant increase in production of reactive oxygen-derived species (ROS) and aggravation of inflammatory condition. Currently, asthma treatment is based on long-term control medications as corticosteroids or leukotrienes modifiers that often cause serious side effects with a considerable price.
The present invention now demonstrates that treatment with the metal complexes of the invention and combinations thereof, reduces the buildup of ferritin-bound labile iron in asthma-related inflamed tissues accumulation of tissue ferritin and the total amount of ferritin-bound iron. The invention further demonstrates reduction of eosinophils and lymphocytes numbers in the peribronchial and alveolar regions, attenuation of the damage to the airway epithelium and mucus overproduction, reduction in neutrophils in bronchoalveolar fluid, reduction of mucous content score, reduction of peribronchial infiltrate value, reduction of epithelial cells metaplasia, reduction of fibrous connective tissue, down-regulation of lungs-ferritin content and its saturation with iron.
Diabetes Mellitus
Diabetes is a disease characterized by failure of insulin feedback and secretion in the beta cells of the pancreatic islets of Langerhans and is one of the most common endocrine diseases across all age groups and populations. The most obvious metabolic effect in diabetes is chronic, erratic elevation of the blood glucose level which is associated with progressive damage to blood vessels. This may lead to heart attack, stroke, blindness, peripheral nerve dysfunction, and kidney failure.
Presently there are 18.2 million people in the United States alone, and 171 millions worldwide who have diabetes. In addition to the clinical morbidity and mortality, the economic cost of diabetes is huge, exceeding US$90 billion per year in the United States alone, and the prevalence of diabetes is expected to increase more than two-fold by the year 2030.
There are two major forms of diabetes mellitus: insulin-dependent (Type I) diabetes mellitus which accounts for 5 to 10% of all cases, and non-insulin dependent (Type-II) diabetes mellitus which comprises roughly 90 to 95% of cases. Type I diabetes mellitus is an autoimmune disease characterized by progressive destruction of pancreatic beta-cells and most often occurring in children and young adults. The disease is associated with high rate of severe irreversible complications occurring despite the availability of insulin replacement, usually through injections administered 1-4 times daily.
Most therapeutic strategies for treatment or prevention of type I diabetes mellitus are directed to suppression of the autoimmune response in order to prevent beta-cell destruction. Accordingly, various immunosuppressive agents have been considered for preventing the destruction of pancreatic beta-cells and have been attempted, such as glucocorticoids, cyclophosphamide, cyclosporin A, rapamycin, FKS06 and prodigiosin. However, the use of such immunosuppressive agents may cause severe side effects such as drug-related toxicity to liver or kidney and to increased incidence of infectious complications, particularly in patients with diabetes mellitus that are already susceptible to infections as part of their disease.
Type II-diabetes results from a compromised insulin production combined with insulin resistance which reflects the inability to properly use insulin. Type II is oftentimes associated with aging. These diabetes, patients typically begin therapy by following a regimen of an optimal diet, weight reduction and exercise. Drug therapy is initiated when these measures no longer provide adequate metabolic control. Initial drug therapy includes sulfonylureas (for example, tolbutamide, chlorpropamide and glibenclamide), biguanides (for example, metformin and buformin), peroxisome prolifrator-activated receptors (PPAR) activators (for example, pioglitazone and rosglitazone) and alpha-glucosidase inhibitors (for example, acarbose and voglibose). However, over 50% of all diabetics treated by presently available drugs demonstrate poor glycemic control and, within six years, require insulin replacement therapy as the last resort.
Although many of the symptoms of diabetes mellitus may be controlled by insulin therapy, the long-term-complications of both type I and type II diabetes mellitus are severe and may reduce life expectancy by as much as one third. Over time, elevated blood glucose levels damage blood vessels, the heart, eyes, kidneys, the nervous system, skin, connective tissue, and white blood cell function.
Moreover, insulin therapy may result in insulin allergy, insulin resistance, atrophy of the subcutaneous fat at the site of insulin injection (i.e., lipoatrophy), enlargement of subcutaneous fat deposit (i.e., lipohypertrophy) due to lipogenic action of high local concentration of insulin, and insulin edema.
The present invention surprisingly shows that treatment with the metal complexes of the invention prevents the development of key diabetes type II pathologies, including hyperglycemia, increased protein oxidation and degradation, decreased protein activity, and cataract formation. Moreover, although the metal complexes of the invention cannot restore destroyed pancreatic beta cells lost due to diabetes type I, the complexes appear to ameliorate physiological manifestations of the disease.
Psoriasis
According to the US National Institutes of Health Medical Encyclopedia, website http://www.nlm.nih.gov/medlineplus/ency/article/000434.htm, psoriasis affects about 2.7% of the people of the world. In the United States, about 3 million people show symptoms of psoriasis at any given time. Psoriasis may affect any or all parts of the skin, but it is more commonly seen on the skin of the trunk, elbows, knees and/or scalp, on skin folds, or in the fingernails and/or toenails. Psoriasis may be aggravated by injury or irritation, such as cuts, burns, rashes or insect bites. It is particularly severe in immuno-suppressed people, like those with AIDS or undergoing chemotherapy for cancer, and in people who have other autoimmune disorders, such as rheumatoid arthritis. In psoriatic arthritis, both a joint and the skin are affected.
When the skin is healthy, it takes about a month for new skin cells to move up from the lower layers to the surface of the skin. In psoriasis, this process takes only a few days, and it results in the build-up of dead skin cells and formation of thick scales.
Keratinocyte proliferation is characteristic of psoriasis. Symptoms of psoriasis include patches of skin that can (a) be dry and/or red; and/or (b) be covered with silvery scales; and/or (c) be raised; and/or (d) have red borders; and/or (e) crack and/or become painful; and/or (f) be discrete and/or demarcated. Additional symptoms may include, for example, (a) skin lesions, such as pustules; and/or (b) cracking of skin; and/or (c) skin redness and/or inflammation; and/or (d) itching; and/or (e) small scaling dots on the skin, especially in children; and/or (f) joint pain or aching, which may be associated with psoriatic arthritis. Further abnormalities in psoriasis may include, for example, nail abnormalities; genital lesions in males; and burning, itching, discharge or increased tearing of the eye.
Psoriasis is considered to be an immune disease. It is classified in many recent publications as an autoimmune disease, a class of diseases in which the immune system targets the body's own cells. Publications suggest that psoriasis is a type I autoimmune disease, mediated, for example, by interferon (IFN) gamma and/or other inflammatory cytokines, and/or by T-lymphocytes. For example, IFN-gamma-producing CD4+Th1-lymphocytes are considered to be of importance in the pathogenesis of psoriasis, as they influence differentiation and functioning of antigen presenting cells, mast cells, neutrophils and endothelial cells. The inflammatory cascade provokes neo-angiogenesis in the dermis and proliferation of keratinocytes. It has been recently reported that CD11c+ cells with markers of dendritic cells are a major cell type in the skin lesions of psoriasis. These CD11c+ cells, which are evident in both epidermis and dermis, are sites for expression of two mediators of inflammation in diseased skin, inducible nitric oxide synthase (iNOS) and TNF-alpha. These cells also express HLA-DR, CD40, and CD86 and the dendritic cell maturation markers DCLAMP and CD83.
Mild psoriasis is currently treated with non-steroidal anti-inflammatory drugs (NSAIDs), exemplified by topically applied salicylic acid and its orally taken derivative, aspirin (known to inhibit NF-.kappa.B); topically applied coal tar; orally taken vitamin D derivatives, like calcipotriol; UV-B phototherapy; and topically applied glucocorticosteroids, like betametasone, known to down-regulate CCL27. Combinations of these are often used. Traditional treatments of severe psoriasis include systemic, orally taken, disease-modifying anti-rheumatic immunosuppressive drugs (DMARDs), like methotrexate, cyclosporin, psoralen plus UVA (PUVA), oral retinoids and fumaric acid esters, gold salts and leflunomide. More recently, biological drugs were introduced to treat severe psoriasis. These include (a) T-cell count lowering AMEMIVE® (alefacept), a recombinant protein binding to CD2 on memory-effector T lymphocytes, inhibiting their activation and reducing the number of these cells. It is a fusion protein composed of leukocyte function-associated antigen type 3 (LFA-3) protein and human IgG1 Fc domains, systemically administered by intramuscular injection. (b) RAPTIVA® (efalizumab), which is a humanized monoclonal antibody against the CD11a subunit of leukocyte function-associated antigen-1 (LFA-1). CD11a is a T-cell surface molecule, important in T-cell activation, T-cell migration into skin, and cytotoxic T-cell function. RAPTIVA® (efalizumab) binds to the CD11a on T-cells and reversibly blocks the interaction between LFA-1 and its adhesion partner molecule ICAM-1. Weekly systemic injections of RAPTIVA® (efalizumab) must continue indefinitely to maintain improvement. (c) ENBREL® (etanercept), a human TNF-alpha receptor, made by fusing two natural TNF-receptors. Its affinity for TNF-alpha is greater than that of the natural monomeric TNF-alpha receptor of the immune system. ENBREL® (etanercept) is systemically administered, and deactivates TNF-alpha upon binding. (d) HUMIRA® (adalimumab), a human IgG1 monoclonal TNF-alpha-binding and inactivating antibody, is used for treating psoriatic arthritis Unlike the other TNF-alpha inhibitors, it is locally injected. (e) REMICADE® (infliximab), a chimeric (mouse-human) IgG1 monoclonal antibody, which binds to and inactivates TNF-.alpha, and administered by systemic injection.
There is a need for a safe, less expensive, topically applied drug for psoriasis management. The biological drugs ameliorate the symptoms of, but do not cure, psoriasis. All five biological drugs listed above are injected, and the injections must continue indefinitely. Topically applied compositions are needed, as these could be safer than the injected or otherwise systemically, e.g. orally, administered drugs, injected and otherwise systemically administered drugs being more likely to affect also organs other than the targeted psoriatic skin. There is also a need to reduce the heavy financial burden associated with treating psoriasis. The annual cost of treating psoriasis with any of the five biological drugs in the USA is between about $15,000 and about $20,000 to $30,000, an amount representing about half of the annual income of many U.S. wage earners. The price of cyclosporine is also high, the drug costing annually about $10,000.
Although the non-biological drug cyclosporin and the biological drugs are generally safe at their dermatological dosage, side effects have been reported. Cyclosporin increases the risk of squamous cell carcinoma of the skin. Adalimumab increases the incidence of serious infections by two-fold, its most notable complication being reactivation of tuberculosis, and also depression syndrome. Among the infliximab treated patients a small percentage reported pneumonia, tuberculosis, lymphoma, drug-induced lupus and hepatotoxicity. Antiefalizumab antibodies developed in approximately 5% of the subjects who were treated with efalizumab. Immune-mediated thrombocytopenia platelet counts at or below 52,000 cells/microliter have been observed in 0.3% of the efalizumab treated patients and four patients developed hemolytic anemia. The overall incidence of hospitalization for infections was 1.6 per 100 patient-years for efalizumab-treated patients compared with 1.2 per 100 patient-years for placebo-treated patients.
The present invention demonstrates that treatment with the metal complexes of the invention is not dermatoxic and significantly reduces psoriasis symptoms, as well as other skin inflammation disorders.
Thus, it is one object of the invention to provide methods using different desferrioxamine-metal complexes, specifically, at least one of Zn-DFO and Ga-DFO for preventing and treating an immune-related disorder, for example, chronic or acute inflammatory-related skin pathologic conditions, respiratory disease, and diabetes.
Another object of the invention concerns combined compositions comprising Zn-DFO and Ga-DFO complexes for treating immune related disorders.
In another object, the invention provides kits combining DFO and metals, specifically, at least one of Zn and Ga, for treating chronic or acute inflammatory-related skin pathologic conditions, respiratory disease, and diabetes.
These and other objects of the invention will become apparent as the description proceeds.